Development of an artificial diet containing green coffee bean extract for grown silkworms

Abstract

 Mulberry leaf powder is the most expensive among the ingredients in the artificial diets of the silkworm, yet it is essential for the growth of normal silkworm strains. In an effort to reduce the cost of artificial diets, green coffee bean extract was considered as the substitute for mulberry leaf powder. The analysis using HPLC revealed that commercial green coffee bean extracts contain more than 20% chlorogenic acid (5-CQA), a feeding stimulant of the silkworm identified from mulberry leaves. Test diets, with defatted soybean meal and corn meal as the main ingredients and varying amounts of green coffee bean extract, were fed to larvae of the normal silkworm strains during the 4th instar. As a result, diets containing more than 0.3% green coffee bean extract were found to be sufficient for larval growth. Based on these findings, a diet for grown silkworms (4th and 5th instar larvae) was developed. The growth performances of silkworm larvae fed the diet was comparable to that of larvae fed a regular commercial diet, suggesting the potential of green coffee bean extracts as a useful and cost-effective feed ingredient for the silkworm.